Gregory Paul Johnson lives in a tiny, off-the-grid house. But, instead of telling us about the environmental benefits (and there are plenty), he's focused on how moving into a 140-sq-foot house has improved his happiness and health.

In an excerpt from his book, Put Your Life on a Diet: Lessons Learned from Living in 140 Square Feet, Johnson explains that he built the home after being inspired by Jay Shafer. In three months, he completed his home, sold his car, and completely changed his life.

He felt happier, he slept more, he found that he had more time for his hobbies and interests, he began saving money, and he lost 100 pounds. The story is pretty inspiring. And makes an interesting, almost non-environmental case for living small.